The present invention broadly relates to a work-handling apparatus, and more particularly to an improved control system for a conveying apparatus of the so-called straight-line type employing one or a plurality of carriages which are independently movable with respect to each other along an aligned series of treating stations and which carriages incorporate one or a plurality of lift mechanisms thereon providing therewith an automatic transfer of work-pieces through the treating stations in a preselected ordered sequence.
Work handling apparatuses, of the general type to which the present invention is applicable, are in wide-spread commercial use for automatically transporting workpieces between successive manufacturing or treating operations. Conveying apparatuses of this type have been found particularly suitable for conveying workpieces automatically through a sequentially phased chemical treating process which frequently includes one or more electro-chemical or electroplating operations. In conveying apparatuses of the preferred type to which the control system comprising the present invention is applicable, one or a plurality of work carriages are mounted on suitable rails or tracks extending along a series of treating stations which are independently driven and independently movable with respect to each other. Each work carriage incorporates one or a plurality of lift mechanisms, thereon including work-engaging means for independently raising and lowering the work-pieces or work racks on which the workpieces are suspended into and out of the treating stations disposed therebelow. The longitudinal travel of each carriage and the elevating and descending movement of each of the lift mechanisms thereon are automatically controlled so as to provide a preselected transfer the workpieces from one station to the next succeeding station in a preselected order sequence.
In conveying apparatuses of the foregoing preferred type, it is frequently desirable to employ a cell-type plating operation along certain portions of the treating stations and a conventional sequential transfer of the work racks through other portions of the treating stations. In machines of considerable length requiring a large number of work carriages each incorporating at least one lift mechanism thereon, the controls for providing an automatic and independent movement of the work carriages and the lift mechanisms thereon becomes relatively complex which is further aggravated by the necessity of providing means to assure coordination of the several work carriages to avoid physical conflict therebetween along those portions of the treating stations where an overlapping movement of adjacent work carriages occurs.
Control systems of the type heretofore known have been found inadequate in providing the requisite flexibility and versatility to permit modifications in the operating sequence of the several machine components as is required from time to time to adapt the work-handing apparatus to an alternative operating cycle. Additionally, control systems of the type heretofore known are further characterized by their relatively cumbersome circuitry requiring a multitude of operative components, substantially increasing the susceptibility of malfunction of the control system as well as increasing the difficulty of servicing the control system and effecting desired modifications in the operating cycle provided thereby as may be required from time to time.
The system of the present invention basically comprises a fully automatic control for a conveying apparatus, for example, an electrochemical plating machine, the entire operation of the plating machine being preprogrammed in a simple, inexpensive form. The recording may take the form of a punch-paper tape, magnetic tape, or the like, which is capable of being read by suitable tape reader, card reader, etc.
This system is provided with suitable sensing and control subsystems which are capable of automatically conveying a piece of apparatus, for example, a plating barrel, through a series of plating steps so that an operator need merely provide the system with a plating barrel including the work pieces stored therein, and a suitable position for removing the work from the plating line. The system will automatically sequence the barrel through the various tanks in the plating line, including timing certain portions of the cycle, and deposit the barrel at the end of the line when the plating process is complete.
The system will be described in accordance with a breakdown of subsystems which were evolved by grouping certain systems on a single circuit board. The system of the present invention will be described in conjunction with a tape reader and a binary coded address system utilized in conjunction with an electrochemical plating apparatus. However, it is to be understood that other systems may incorporate features of the present invention and other types of input storage devices may be utilized. Listed below is the presently assigned letters, their use in the system and the code. The code used is the standard ASCll code.
__________________________________________________________________________ SYM FUNCTION # 1 2 3 4 5 6 7 __________________________________________________________________________ O O O O O O X O : Read Flag Switches & Reset Block Ctr. 1 X O O O " 2 O X O O # 3 X X O O $ 4 O O X O % 5 X O X O & Incoming Interlock Interrogate 6 O X X O ' 7 X X X O ( Open Timer Register 8 O O O X ) Close Timer Register 9 X O O X * 2nd Digit-Multi Stations 10 O X O X + Turn on-interlock (outgoing) 11 X X O X , Index Block Counter 12 O O X X - Turn off-interlock (outgoing) 13 X O X X . Reset Block Counter 14 O X X X 15 X X X X O X O __________________________________________________________________________ 0 O O O O O X X O 1 1 X O O O 2 2 O X O O 3 3 X X O O 4 Station Address Numbers 4 O O X O 5 (Always 2-"21" or "06" etc. 5 X O X O 6 6 O X X O 7 Or timer selector 7 X X X O with "("and")" 8 O O O X 9 9 X O O X : 10 O X O X ; 11 X X O X &lt; Not Used 12 O O X X = 13 X O X X &gt; 14 O X X X ? 15 X X X X X X O __________________________________________________________________________ LF "Line Feed" 10 O X O X O O O __________________________________________________________________________ 0 Tape Home O O O O O O O X A Auxiliary Stop 1 X O O O B Second Lift System 2 O X O O C ##STR1## 3 X X O O D Hoist (S) Down 4 O O X O E F G H I J K ##STR2## 5 6 7 8 9 10 11 X O X O X O X O X X O O X X X X X O O O O O O O X X X X L Left Transfer 12 O O X X M N ##STR3## 13 14 X O O X X X X X .phi. 15 X X X X O O X __________________________________________________________________________ P O O O O O X O X Q 1 X O O O R Right Transfer 2 O X O O S Slow Speed Only-Lifts or Trans. 3 X X O O T 4 O O X O U Hoist (s) Up 5 X O X O V Intermediate Stop No. 1 top 6 O X X O W Intermediate Stop No. 2 bottom 7 X X X O X 8 O O O X Y 9 X O O X Z Reset Step-No Counter 10 O X O X [ Open Alternate Cycle Register 11 X X O X ##STR4## 12 O O X X ] Close Alternate Cycle Register 13 X O X X ##STR5## 14 O X X X ##STR6## 15 X X X X X O X __________________________________________________________________________ CR "Carriage Retrun" & Stop Tape 13 X O X X O O O __________________________________________________________________________
One portion of the system includes a tape reader control circuit which is adapted to control the operation of the tape reader by providing stepping pulses to step the reader through a sequence of codes and also means is provided to initially home the tape at a preselected starting position. This circuit also includes a circuit for reading the various coded holes in the punched tape and transmitting the sensed code in a usable form to the remainder of the system. Also, a circuit is provided to record the number of steps which have occurred since the start or home position of the tape and display the result.
Another portion of the system includes a station address register circuit which is adapted to read a particular station from the tape and store this address in the circuit. Subsequently, when the conveying mechanism is moving down the line, reading each address as it approaches the station, the read address will be compared to a stored address and an output signal will be provided when a coincidence is achieved. Also, a converter circuit is included to convert the binary coded decinal representation of the set address and provide an indication of this set address to the operator. Upon achieving the specified station, an output signal is generated to change the motor speed to low speed and enable a stop switch circuit so that the motor may be stopped exactly at the point on the station wherein the conveying mechanism is directly above the work.
The next circuit included in the system of the present invention is a multi-station register which is utilized in conjunction with a tank having a plurality of stations therein when it is desired to store an address code within the system to signal when a particular station within the multi-station tank is to be utilized. A code has been selected, in this case an asterisk, to indicate to the system that a particular stored number within the system is to be utilized and fed back into the system as the next address to which the conveying apparatus is to proceed. In this way, the length of tape required for a specific program will be substantially reduced. This is because a group of tanks referred to as a multi-cell tank are, for this purpose, considered as one tank. The system is thus capable of providing an address for the conveyor apparatus from within the system rather than reading the address on the storage tape or the like. The system also includes a circuit for indexing the stored address to permit the carrier unit to deliver a plating barrel to a first address in a multi-station tank and subsequently pick up a second plating barrel from another address and deliver a third plating barrel to that same address.
The system further includes a transfer control circuit which responds to left and right commands from the tape and also responds to an auxiliary stop signal and a slow speed only signal. With this circuit, the system is commanded to go either left or right to a particular address which is either generated by the reader tape or is generated within the system as described above.
The system further includes a lift control system which responds to up and down commands from the tape and also responds to two commands for intermediate stopping positions. With this circuit the lifting mechanism can be commanded to go up, down or to either of two intermediate stopping positions. These intermediate stopping positions may be used as necessary to align with a load stand that is not at either the full up or full down position.
As is common in the electroplating arts, certain portions of the electroplating process must be timed in order to achieve the desired results. To this end, suitable timers, certain being fixed and certain being variable, are provided to time these portions of the precess. The system also includes an alternate cycle register which renders the system capable of performing a secondary program in response to external signals and subsequently returning to the main program and completing the steps of the main program.
Accordingly, it is one object of the present invention to provide an improved control system for a conveyor apparatus.
It is another object of the present invention to provide an improved control system which is particularly adaptable for use in conjunction with a plural position electrochemical plating apparatus.
It is another object of the present invention to provide an improved completely automatic system for controlling the operation of a conveying apparatus including longitudinal and vertical travel.
It is still a further object of the present invention to provide an improved preprogrammed control system for a work conveying apparatus which includes an increased simplification of the preprogrammed apparatus.
It is still another object of the present invention to provide an improved control system wherein the system incorporates a system for controlling the longitudinal travel of the work carriage and actuation of the lifting mechanisms thereon to provide an interlocking system to correlate the movements of adjacent carriages.
It is still another object of the present invention to provide an improved control system for conveying apparatus which substantially simplifies the circuitry as well as eliminating a substantial number of subsystems required for effecting a controlled automatic sequentially phased operation of each of a plurality of work carriages.
A further object of the present invention is to provide an improved control system for a conveying apparatus which is more versatile than systems of the type heretofore known enabling modifications to be made in the programmed movement of the work carriages in order to adapt the carriages to alternate processing cycles without encountering difficulty or sustaining excessively long machine down time periods during modification.
It is still a further object of the present invention to provide an improved control system for a work handling apparatus wherein the programming device operates independently of the movement of the work carriage except at preselected points.
It is still another object of the present invention to provide an improved programmed control system for a work carriage, including a longitudinal travel and boisting mechanism, wherein the program storage device is greatly simplified and may be preprogrammed remote from the conveying apparatus, such as a printed tape, magnetic tape or a punched paper tape.
It is still a further object of the present invention to provide an improved preprogrammed control system for a work conveying apparatus wherein the programmed travel of the conveying apparatus may be easily changed by merely replacing one preprogrammed device by a modified preprogrammed device.
It is still a further object of the present invention to provide an improved preprogrammed automatic control system for a work conveying apparatus which is extremely high speed in operation and is substantially completely electronically controlled.
It is still a further object of the present invention to provide an improved automatic control system for a work conveying apparatus which incorporates improved position indicating systems for the position of the longitudinal movement of the conveying apparatus or the hoisting movement of the apparatus.
It is still a further object of the present invention to provide an improved addressing system for a conveying apparatus which is utilized to automatically switch the conveying apparatus from one speed to a second speed in response to a sensed position which approaches the ultimate position.
It is still a further object of the present invention to provide an improved control system for a work conveying apparatus. such as an electrochemical plating apparatus, which utilizes extremely simplified command signals, as for example single letter commands, controlling the operation of the system.
It is still a further object of the present invention to provide an improved control system for conveying apparatus which is capable of insuring that the conveying mechanism for the work is at the proper position, both in the longitudinal and up and down direction, during the operation of the system.
It is still a further object of the present invention to provide an improved control system for an electroplating or other work conveying apparatus which is capable of automatically carrying a work load through a system including providing timing for various portions of the operations being performed on the work.
It is a further object of the present invention to provide an improved control system for a work conveying apparatus which is reader controlled and includes a system for automatically homing the data storage device within the reader at a preselected starting position, certain data being retained within the system during the homing process.
It is a further object of the present invention to provide an improved system for storing and displaying the number of steps which have been fed into the system for control of the conveying apparatus from the reader.
It is another object of the present invention to provide an improved system for use in a work conveying apparatus which incorporates an improved desired address as compared to actual address comparison circuit to establish when the conveying apparatus has achieved the desired position within the system.
It is still a further object of the present invention to provide an improved control system for use in conjunction with a multi-station section for a system performing work on a work piece wherein the system stores within itself the data as to when a particular portion of the multistation area is being utilized or not being utilized.
It is a further object of the present invention to provide an improved control system for a work conveying apparatus incorporating a multi-station position wherein the system is capable of generating addresses for the work conveyor within the system to command the conveyor to retrieve or deposit a piece of work at a particular address within the system.
It is still a further object of the present invention to provide an improved control circuit for a conveying apparatus usable in a multi-station system such as described above wherein the system includes a circuit for indexing the address generated within the system.